November 15, 2018

I’m running behind in my fall garden projects including taking care of the fallen leaves all over my lawn. Maybe it just feels like I’m behind because of the snow we’ve been having recently.

This past weekend while driving back from up north, I spotted several people catching up on their fall tree leaf clean up. They were easy to spot because of the plumes of smoke rising up from their lawns and ditches. By the way, this was happening out in the countryside where leaf burning is still fairly common.

I enjoy the smell of burning leaves as much as the next guy. When I smell leaf smoke, it reminds me of my childhood when nearly everyone in the neighborhood burned their leaves. It actually was a pretty good tactic to get the kids out of the house. As a matter of fact, the neighborhood kids looked forward to raking the lawn because of the fire afterward.

Of course nowadays most communities have ordinances restricting leaf burning. And Michigan has a state law regulating open burning of leaves so we don’t see or smell much of it anymore.

As much as I enjoy it, as a gardener I wouldn’t burn leaves even if it were allowed. They are just too valuable as a soil amendment to let them just go up in smoke.

Valuable soil building components found in leaves are destroyed by burning.

I you think about it for a bit, trees have huge root systems that absorb soil minerals from a deep and wide area, nutrients that may not be available to other kinds of plants. Those soil nutrients, along with carbon from the atmosphere, are used by trees to make their leaves. That’s a lot of plant nutrients that trees make for us when you consider the shear volume of leaves each tree produces every year.

The mineral components of the leaves quite are valuable, providing much more fertilizer value than manure. Even more valuable than the mineral elements are the carbon compounds that make up the bulk of a leaf. When leaves break down in the soil they provide humus, that magical ingredient that experienced gardeners know is the secrete to a flourishing garden.

I remember several years ago a friend of mine used to pick up bagged up leaves from the curbside in the city and take them home to use because she didn’t have access to enough leaves. One day just as my friend was about to depart with a van full of bagged leaves, the homeowner came running out of the house shaking her fist and yelling, “put those leaves back!” The funny thing is those leaves were about to be picked up by the trash collectors and taken to the landfill.

The biggest drawback to leaves is their tendency to blow around and not stay put where they are needed. That can easily be taken care of by cutting them up into smaller pieces. I use a leaf vac with a collection bag to shred and collect most of my leaves. Some of the heavier and tougher leaves like cottonwood, I run over with a lawn mower first to make them easier to vacuum up. Then they either go right into the garden as a mulch or into to the compost pile if there are any left over.

Instead of looking at leaves as trash that needs to be bagged up and hauled away, I like to consider them free soil builders provided by mother nature every year. In case you were wondering, my friend did manage to escape with her misbegotten load of contraband.

March 21, 2018

It’s tempting to prune fruit trees in early March especially on warm, sunny days when were out in the yard looking for some thing to do. Usually it’s fine to do so, but I like to wait to prune until after the chance of freezing rain has past.

A heavy accumulation of ice during an ice storm is liable to break off branches from fruit trees. That can be a real problem if a major scaffold branch is lost.

In many cases the tree can grow new scaffold branch from existing nearby shoots. It’s the gardeners job to select which shoot would make the best replacement. If you do all your pruning early, you greatly reduce the number of shoots available for growing the replacement branch.

You can however to do part of your pruning now and save the rest for later without losing any potentially valuable wood. Early March is a very good time to prune off all of the water sprouts that have grown from during the previous season.

Water sprouts are those thin branches that grow straight up from the main branches.

During a severe ice storm, ice can add from ten to one hundred times the weight the weight that branches have to support. High winds make it even more hazardous for the trees. By removing water sprouts you drastically reduce the surface area for ice to collect, lightening the load that fruit trees branches have to bear. One quarter to one half inch of ice can cause small branches to begin breaking. Taking off the sprouts also reduces the amount of area for the wind to push against.

Water sprouts need to be pruned off eventually as a regular part of fruit tree pruning. They reduce much needed air circulation making conditions more conducive to diseases. With their rank growth, they also keep sunlight from reaching the fruiting parts of the tree.

During a normal year we can expect four or five days when ice accumulates and usually is not enough to do much damage. But every ten to twenty years or so we get a major ice event and that’s when trees get damaged. By doing your fruit tree pruning in two stages you can buy yourself a little extra insurance against major tree damage.

Maybe you’ve seen pruning being done in large commercial orchards as early as February. They prune that early because of the sheer number of trees that need to be pruned and don’t have the time to go through the orchard twice.

February 27, 2018

We still have plenty of winter left to go until spring arrives. In the meantime you can bring a little bit of spring early into your home by forcing shrub and tree branches into budding out of season.

The shrub everyone thinks of first is pussy willows with their irresistible silver, fuzzy buds. There are others that you can force into budding but you have to start now if you want results before spring. Some species of woody plants, such as forsythia, may take only a couple weeks to bloom while other plants may take a month or more.

Fruit trees like apple, cherry and pear can produce showy flowers. Others like maple tree branches are more subtle with their separate male and female flowers.

Magnolia buds may not blossom but will swell and provide you with some spring color.

Aspen and other poplar trees will often send out a pendulous spray of flowers that remind you of warm days ahead. Many other species will reward you with green leaves that have their own charm when viewed up close. Indoors, some leaves even have a faint spring-like fragrance that is lost in the great outdoors during their normal budding season.

Forcing branches is a great excuse to use your special flower vase that has been sitting empty or that rustic flower container. It’s fun to experiment with forcing different types of trees and shrubs. Here’s a list to help you get started: for flowers try forsythia, dogwood, pear, cherry, plum, quince, apple, crab apple, currants, maple and willow. For leaves: beech, poplar and roses.

It’s important to start early because of the time it takes for the branches to respond to being brought inside where it’s warm. Make sure to use sharp pruning shears to make nice clean cuts with no ragged edges. Change the water in your container from time to time to keep it fresh and free from algae.

Use your artistic eye to arrange your branches in an attractive way since you’ll be looking at them for a few weeks without anything noticeable happening. Keep in mind the buds are very fragile once they start opening and can easily be broken off if you’re not careful.

September 19, 2017

In many cases, diagnosing plant problems requires an in-person look at the plant in question. Too many disorders look similar when all you have is a photo to go by.

Earlier this week someone sent me a photo asking about spots on a valuable tree they have in their front lawn. That was an easy one. I took one quick look at the photo and knew right away what it was. Their maple tree was infected with a fungal disease called “tar spot”. It’s quite easy to identify because in this case the name is very descriptive, the leaves really do look like they’re covered with spots of tar.

A classic example of tar spot.

Even though it looks pretty bad, tar spot is relatively harmless even in a heavily infected situation. There’s no good way of preventing the disease. Some years are worse than others for tar spot and some varieties seem to be disposed to having more dramatic symptoms than others.

The spores from the disease over winters in fallen leaves so you wound think that raking them up and disposing of them would help the situation. Unfortunately the fungal spores can travel for miles in the air and can land on your tree and take hold.

When a tree has a severe case of tar spot, it can lose many of its leaves causing the tree raking season tobegin earlier than normal.

One bright spot is: since tar spot is species specific, it will not spread to other types of trees such as oaks.

August 31, 2017

The stretch of dry weather we had took its toll on some sycamore trees planted in a less than ideal spot this season. Although sycamores can grow in dry areas, they thrive in moist soils. That causes a bit of a problem since the best spot to build a structure is on a high and dry area — the exact opposite of the what is preferred by a sycamore tree.

People love sycamores because of their maple-like leaves and unique bark. A healthy, thriving sycamore is a wonderful sight and is makes fine shade tree, although they can be messy. However, unless a building site has a low, moist spot, a sycamore should not be your first choice. When these trees are planted on the wrong site, they never get a chance to live up to their full potential. A dry site can actually significantly shorten their lifespan.

Powdery mildew is a plant disease that can show up this time of year on sycamores. And that is exactly what happened on a trio of sycamores I was asked to look at last week. Usually powdery mildew shows up first on the newest leaves, but on those trees so many leaves were gone, I was only able to find the fuzzy fungus growth on the few older leaves still attached to the tree.

This sycamore has lost virtually all of its leaves. Compare that to the maples in the background that have nearly all of their leaves.

Normally mildew is not a serious problem on sycamores, it causes leaves to drop but the trees bounce right back the next season. I’m somewhat concerned about those three trees. The combination of the dry site and powdery mildew may leave the trees in a permanent weakened condition. Healthy sycamores are fast growing trees but these seem to be languishing in that spot. The prescription in this case is to irrigate the trees as soon as the start of a dry spell is expected — every year from here on out.

Since trees can live for decades or even centuries, take some time to survey your planting site and match the tree to the conditions.